Technical Field
Embodiments of the present disclosure are directed to optical sensor packages.
Description of the Related Art
Optical sensors, such as proximity sensors, are used to detect the presence of nearby objects and are able to do so without physically touching the object. Some types of optical sensors, such as utilized in optical ranging devices or time of flight sensors, may be used to determine the actual distance to such nearby objects. Optical sensors may be utilized in various electronic devices, such as cameras, phones, including smartphones, vehicles, machinery, and other devices for detecting the presence of and/or distance to nearby objects. After detecting the presence of the nearby object, the electronic device may be configured to perform a function, such as move a mechanical feature to a secure position, transmit an alarm signal, couple or uncouple an electrical communication, or any other desired function.
Optical sensor packages typically include a light-emitting device (e.g., a LED), a light-receiving sensor, such as a photodiode, and a processing chip for processing signals received from the light-receiving sensor. The LED, photodiode and processing chip are typically formed on separate dies and packaged together in a sensor package. Generally described, the LED emits radiation out a first opening in the sensor package. When an object is close to the sensor package, a suitable amount of the emitted radiation is reflected off of the object and back toward the sensor package. Some of the reflected radiation enters a second opening in the sensor package proximate the light-receiving sensor or photodiode. The photodiode receives the reflected radiation and generates an electrical signal indicative of the received radiation, which is transmitted to the processing chip for processing, e.g., to determine the presence of and/or distance to the proximate object.
The light-emitting device and light-receiving and processing devices in conventional optical sensor packages typically provided in a side-by-side configuration, which results in a product having a wide footprint (i.e., x and y dimensions), or in a chip-on-chip or stacked chip configuration, which results in a product having a thick package (i.e., z dimension).